docs: def narrow_sqs(self, sqs):
          """
          TODO: Currently this is an AND conjunction. It should vary depending
          on the value of self.select_many.
          """
          if self.select_many:
              sq = None
              for value in self.get_applicable_values():
                  q = SQ(**{self.field_name: sqs.query.clean(value.value)})
                  if sq:
                      sq = sq | q
                  else:
                      sq = q
              if sq:
                  sqs = sqs.narrow(sq)
          else:
              for value in self.get_applicable_values():
                  sqs = sqs.narrow(
                      u'%s:"%s"' % (self.field_name, sqs.query.clean(value.value))
                  )
  
          return sqs